Corrosion inhibiting composition containing acetylenic alcohols a quinoline quaternary compound and an organic fluoride

ABSTRACT

CORROSION OF FERROUS METALS BY CORROSIVE ACIDS AT ELEVATED TEMPERATURES IS INHIBITED BY ADDING TO THE CORROSIVE ACID A COMPOSITION COMPRISING EFFECTIVE AMOUNTS OF AT LEAST 2 ACETYLENIC ALCOHOLS, A QUINOLINE QUATERNARY COMPOUND AND AN ORGANIC FLUORIDE HAVING THE STRUCTURE:   1-Y,2-(CNF(2N+1)-)-2-IMIDAZOLINIUM (X.3H2O)(-)   WHERE N IS AN INTEGER FROM 3 TO 10; X IS SELECTED FROM THE GROUP CONSISTING OF BROMINE AND IODINE; AND Y IS A GLYCOL HAVING 3 TO 10 CARBON ATOMS. THE COMPOSITION MAY CONTAIN A TERPENE ALCOHOL, AN ALIPHATIC ALCOHOL AND A DISPERSING AGENT SUCH ASS AN ETHOXYLATED OLEATE AND THE LIKE.

United States Patent O 3,658,720 CORROSION INHIBITING COMPOSITION CON- TAINING ACETYLENIC ALCOHOLS, A QUINO- LINE QUATERNARY COMPOUND, AND AN ORGANIC FLUORIDE Lee A. McDougall and James R. Looney, Houston, Tex., assignors to Esso Research and Engineering Company No Drawing. Filed Nov. 12, 1969, Ser. No. 876,126 Int. Cl. C23f 11/04, 11/14 US. Cl. 252-392 15 Claims ABSTRACT OF THE DISCLOSURE Corrosion of ferrous metals by corrosive acids at elevated temperatures is inhibited by adding to the corrosive acid a composition comprising effective amounts of at least 2 acetylenic alcohols, a quinoline quaternary compound and an organic fluoride having the structure:

where n is an integer from 3 to X is selected from the group consisting of bromine and iodine; and Y is a glycol having 3 to 10 carbon atoms. The composition may contain a terpene alcohol, an aliphatic alcohol and a dispersing agent such as an ethoxylated oleate and the like.

BACKGROUND OF THE INVENTION (1) Field of the invention The present invention is directed to corrosion inhibition of corrosive acids. More particularly, the invention is concerned with inhibition of corrosive acid in contact with ferrous metals. In its more specific aspects, the invention is concerned with a method and composition for inhibiting corrosion of ferrous metals by corrosive acids in which the composition comprises at least 2 acetylenic alcohols, a quinoline quaternary compound and an organic fluoride having the structural formula:

where n is an integer from 3 to 10; X is selected from the group consisting of bromine and iodine; and Y is a glycol having 3 to 10 carbon atoms or is an ethoxylated alcohol having 1 to 10 moles of ethylene or propylene oxide.

(2) Description of the prior art It is known to use organic and inorganic fluorides as corrosion inhibitors. It is also known to use one or more acetylenic alcohols as corrosion inhibitors. The use of amines and various nitrogen compounds as corrosion inhibitors is also old in the art. Most corrosion inhibitors have been largely ineffective in combatting the corrosive effects of corrosive acids such as mineral acids, particularly at elevated temperatures.

The use of perfluoroalkylimidazolines as corrosion inhibitors as such or as the fatty acid salts has also been taught in hydrocarbon media. However, the combination of a particular organic fluoride, at least 2 acetylenic alcohols and quinoline quaternary compounds such that the combination is more effective as a corrosion inhibitor than any of its components has not been taught as a 3,658,720 Patented Apr. 25, 1972 "ice corrosion inhibitor for corrosive acids in contact 'with ferrous metals.

Prior art considered with respect to this invention include the following listed US. patents:

SUMMARY OF THE INVENTION The present invention may be briefly described and summarized as involving a corrosion inhibitor composition comprising effective amounts of at least 2 acetylenic alcohols, a quinoline quaternary compound, and an organic fluoride having the structural formula:

where n is an integer from 3 to 10; X is selected from the group consisting of bromine and iodine; and Y is a glycol having 3 to 10 carbon atoms or is an ethoxylated alcohol having 1 to 10 moles of ethylene or propylene oxide.

Optionally the composition may contain a terpene alcohol such as pine oil, an aliphatic alcohol, such as isopropyl alcohol, and a dispersing agent such as an ethoxylated oleate.

The invention also may be summarized as a method of inhibiting the corrosivity of corrosive acids in contact with ferrous metals, such as steel, by adding to the corrosive acid an effective amount of the aforementioned composition.

VARIABLES OF THE INVENTION The acetylenic alcohols employed in the present invention may suitably include ethyl octynol, propargyl alcohol, and other acetylenic alcohols having the structural formula:

2 l H--CEC-C-OH where R is selected from the group consisting of CH, and H and R is selected from the group consisting of H, alkyl groups having 1 to 18 carbon atoms, mono-cyclic aryl groups, naphthalyl, phenyl, and alkyl substituted phenyls having 1 to 10 carbon atoms in the alkyl substituent. Examples of such alcohols include: methyl butynol, methyl pentynol, hexanol, ethyl octynol, propargyl alcohol, benzyl butynol, naphthalyl butynol, and the like.

The quinoline quaternary compounds may be illustrated by alkyl pyridine-methyl chloride quaternary, alkyl pyridine-benzyl chloride quaternary, quinoline-benzyl chloride quaternary, isoquinoline-benzyl chloride quaternary, thioalkyl pyridine quaternaries, thioquinoline quaternaries, benzoquinoline quaternaries, thiobenzoquinoline quaternaries, imidazole quaternaries, pyrimidine quaternaries, carbazole quaternaries, and the like. i

The organic fluoride may be a compound having the structure:

The glycol radical may be derived from the following glycols: ethylene glycol, propylene glycols, other diols, t riols. The ethoxylated alcohol may have 1 to moles of ethylene or propylene oxide.

Similarly, the iodine molecule may be replaced by bromine to form similar bromides rather than the iodides. Where the iodide is used, this organic fluoride is known to the market as Fluorad FC-134. Analysis of this material shows that it has the above structural formula and the empirical formula:

The terpene alcohol may be pine oil, but other terpene alcohols such as alpha, beta and gamma terpineols, borneol, and the like may be used.

An aliphatic alcohol may also be employed in the composition as illustrated by methyl, ethyl, propyl, isopropyl, butyl, pentyl, hexyl, heptyl, octyl and the higher liquid members of these aliphatic alcohols.

Also, an ethoxylated oleate such as ethoxyllated sorbitol hexaoleate and ethoxylated polyol oleate may be used as a dispersing agent. Other ethoxylate doleates, tall oils, and other fatty acids may be used as dispersing agents. In some cases these compounds also act as solubilizing agents as well as dispersing agents.

Typical amounts of the various components of the composition are shown below:

Wt. percent 1st acetylenic alcohol About to about 25. 2nd acetylenic alcohol About 5 to about 10. Quinoline quaternary About 30 to about 50. Organic fluoride About 0.05 to about 1.0. Terpcne alcohol About 15 to about 35. Aliphatic alcohol About 2 to about 6. Ethoxylated oleate or solubilizing agent About 0.25 to about 1.0.

The first acetylenic alcohol may have a higher molecular weight than the second acetylenic alcohol and is used in greater amounts as shown above and in the following embodiments and modes.

The essential components of the present invention are the 2 acetylenic alcohols, the quaternary compound and the organic fluoride all of which cooperate to reduce the corrosivity of corrosive acids. The terpene alcohol serves as a coupling agent and -film forming agent while the aliphatic alcohol performs the function of a solvent. The ethoxylated oleate or other dispersing agent disperses and/or solubilizes the other components of the composition.

DESCRIPTION OF THE PREFERRED EMBODIMENTS AND MODES Two formulations of the present invention were made up as follows:

Percent Ethyl octynol Propargyl alcohol 8 Quinoline quaternary 40 Fluorad FC-134 0.25 Pine oil 23 Isopropyl alcohol 3 Ethoxylated sorbitol hexaoleate 2-2..-- 0.75

' Percent Ethyl octynol 17 Propargyl alcohol 8 Quinoline quaternary 40 Fluorad FC-134 0.25 Pine oil 30 Isopropyl alcohol 4.25 Ethoxylated polyololeate 0.5

Formulations (l) and (2) were then added to a mineral acid in contact with various types of steel under the following conditions with the corrosion rates indicated:

TABLE I.-EFFECT OF METAL TYPE To illustrate the effect of acid type and concentration, the following data are presented:

TABLE II.EFFECT OF ACID TYPE AND CONCENTRATION Conditions:

Metal N-SO. Exposure 24 hours. Temperature 200 F.

Corrosion rate, lbJltfl/day Acid-inhibitor conc.(vol.

percent) 1 2 15% B01, 0.5 0.0087 0. 0038 123% HCl-HF, 0.6 0. 0067 0.0058 28% H01, 2.0 0. 0117 0.0130

The eifect of exposure time is illustrated in the following table:

TABLE III.EFFECT OF EXPOSURE TIME Conditions:

Acid 28% HCl. Metal N-80. Temperature 200 F. Inhibitor conc. :2 vol. percent.

Corrosion rates, 1b./tt. day

Length of exposure (hrs.) 2

The composition of the present invention maintains its effectiveness at high temperature as shown in Table IV:

TABLE IV.EFFECT OF TEMPERATURE Conditions:

ACld 15% HCl. Metal P-105.

Ex- Inhibitor Corrosion rate, 1b.! posure conc. it. '/day time (vol. Temperature, I (hours) percent) 1 2 The acetylenic alcohols alone are not very good in hibitors of corrosion as shown by the following data:

TABLE V.EFFECT OF ACETYLENIC ALCO- HOLS ALONE ACID CORROSION RA'DE Corrosion rate Acetylenic alcohol: lb./ft. day Ethyl octynol 2.4548 Propargyl 2.1529 Hexynol 1.2296 OW-l (lower purity hexynol) 0.7857

' Also, the amines and quaternary compounds can be optimized as illustrated in Table VI:

TABLE VI.EFFECT OF AMINES AND QUATERNARY AMINES Conditions:

Acid HCl. Exposure 24 hours. Temperature 200 F. Inhibitor cone. 0.5 vol. percent.

Corrosion Variation of amine or quaternary in above Metal rate (1b.! compositions coupon itfi/dey) Alkyl pyridine N-80 0. 1617 Alkyl pyridine-methyl chloride quaternary N-80 0. 0830 Alkyl pyridine-benzyl chloride quaternary- N-SO 0. 0075 Quinoline .T-55 0. 0971 Quinoline-benzyl chloride quaternary J -55 0.0571 Sim-refined isoquinoline-benzyl chloride qua- N-80 0.0030

ernary. Quinoliue residue-benzyl chloride quaternary" N-80 0.0041 Quinoline bases-benzyl chloride quaternary"... N 80 0. 0029 Table VII, which follows, shows the effect of varying the acetylenic alcohol concentrations for optimization of basic compositions:

TABLE VII-EFFECT O F ACETYLENIC AL- COHOLS IN COMPOSITIONS Conditions:

Acid 15 HCl. Exposure 24 hours. Temperature 200 F. Inhibitor conc. 0.5 vol. percent.

Corrosion Variation of acetylenic alcohols in above Metal rate (1b.! compositions (percent used) coupon ti/day) Ethyl octynol (15%) plus propargyl (10%) J-55 0.0198 Ethyl octynol plus propargyl (57 J 55 0.1018 Ethyl octyuol P-105 0. 0852 Propargyl (35%).. P-105 0. 0728 Hexynol 2%) P-105 0.0286 OW-l [less pure hexynol] (32%) P-105 0. 0210 Ethyl octynol (20%) plus propargyl(12%) 0. 0097 Ethyl octynol (20%) plus hexynol (12%). 0.0119 Ethyl octynol (20%) plus OW1 (12% 0.0129 Hexynol (20%) plus propargyl (12%). 0. 0362 Hexynol (20%) plus OW l (127 P-105 ow-1 (20%) plus propargyl 12 P-105 It is to be noted that OW-l (a less pure hexynol) is better than the other acetylenic alcohols in inhibiting corrosion. This is because the impurities are other acetylenic alcohols in accordance with the present invention.

In Table VIII a comparison of the effect of various fluorides on corrosion is given.

6 TABLE VIII.EFFECT OF ORGANIC AND IN- ORGANIC FLUORIDES IN COMPOSITIONS Conditions:

Acid 15% HCl. Exposure 24 hours. Temperature 200 F. Metal coupon P-105. Inhibitor conc. 0.5 vol. percent.

It will be clear that the FC-134 fluoride which contained iodine is the only one of the fluorides in Table VIII that showed any effectiveness as a corrosion inhibitor. The bromine containing fluoride may behave in a similar fashion.

The invention has been described and illustrated by reference to metals as J-55, P- and N-80. These are ASTM designations for various well known steels.

The data show that the particular compositions of the present invention are unobviously better than the components thereof and, therefore, the invention may be quite valuable in combatting corrosion of corrosive acids such as sulfuric, nitric, hydrochloric, carbonic acid, acetic acid, other organic acids, and the like against ferrous metals.

The invention may be used in oil and gas fields and well environments since acid is used in acidizing and preventing scale formation by injection into Wells. It may also be used in other acid environments such as in acids used in cleaning ferrous metal equipment such as oil refinery equipment as illustrated by heat exchangers of deposited scale, acid soluble salts, and the like.

The nature and objects of the present invention having been fully described and illustrated and the best modes and embodiments contemplated set forth what we wish to claim as new and useful and secure by Letters Patent is:

1. A hydrochloric acid corrosion inhibiting composition for ferrous metals comprising effective amounts of:

(a) at least 2 acetylenic alcohols having the structural formula:

1 H-CsC-c-B where R is selected from the group consisting of CH and H and R is selected from the group consisting of H, alkyl groups having 1 to 18 carbon atoms, mono-cyclic aryl groups, naphthalyl; phenyl, and alkyl substituted phenyls having 1 to 10 carbon atoms in the alkyl substituent;

(b) a quinoline quaternary compound; and

(c) an organic fluoride having the structural formula:

2. A composition in accordance with claim 1 in which the acetylenic alcohols are ethyl octynol and propargyl alcohol.

3. A composition in accordance with claim 1 containing an effective amount of a terpene alcohol.

4. A composition in accordance with claim 3 in which the terpene alcohol is pine oil.

5. A composition in accordance with claim 1 containing an effective amount of an alkanol.

6. A composition in accordance with claim 5 in which the alkanol is isopropyl alcohol.

7. A composition in accordance with claim 1 containing a dispersing amount of an ethoxylated oleate.

8. A composition in accordance with claim 7 in which the oleate is ethoxylated sorbitol oleate.

9. A composition in accordance with claim 7 in which the oleate is ethoxylated polyol oleate.

10. A composition in accordance with claim 1 comprising:

(a) about 20% to about 35% by wt. of said 2 acetylenic alcohols; (b) about 30% to about 50% by wt. of a quinoline quaternary compound; (c) about 0.05% to about 1.0% by wt. of an organic fluoride having the structural formula:

N M0 rm N H/ CHzCHzO CHzCHzOH and (d) about to 35 by wt. of a terpene alcohol. 11. A composition in accordance with claim 9 in which the acetylenic alcohols are ethyl octynol and propargyl alcohol, and the terpene alcohol is pine oil.

12. A composition in accordance with claim 9 comprising about 2% to about 6% by wt. of an alkanol.

13. A method for inhibiting the corrosivity of a corrosive hydrochloric acid in contact with a ferrous met-a1 which comprises adding to said corrosive acid an inhibiting amount of the composition of claim 1.

14. A method in accordance with claim 11 in which the inhibiting amount is within the range from about 0.25% to about 2.5% by volume based on the corrosive acid.

15. A method in accordance with claim 11 in which the ferrous metal is steel.

References Cited UNITED STATES PATENTS 3,108,968 lO/1963 Tice 252389 3,141,001 7/1964 Vietor 252-389 3,249,548 5/1966 Herman et a1. 252-396 3,382,179 5/1968 Keeney et a1 252-896 3,404,094 10/ 1968 Keeney 252-148 RICHARD D. LOVERING, Primary Examiner 'I. GLUCK, Assistant Examiner US. Cl. X.R. 

